1. Field of the Invention
The present invention concerns a gantry for an x-ray computed tomography apparatus with a device for measurement of the rotation angle of the gantry rotor relative to the gantry stator, and a method for measurement of the rotation angle.
2. Description of the Prior Art
An angle measurement device for the above purpose is known from DE 100 38 296 A1. In this known angle measurement device, magnetically scannable markings are applied on a rotatable disc. Given a rotation of the disc, the markings are scanned by scan heads. A signal generated by the scan heads can be interfered with due to fluctuations in the rotation speed of the disc, due to manufacturing-dependent tolerances in the size and geometry of the disc and/or the markings, as well as due to markings being imprecisely applied on the disc. These interferences lead to a reduced precision of the angle measurement. Attempting to increase the precision by a reduction of the manufacturing tolerances is complicated and cost-intensive.